This invention relates to articles, particularly brass articles, having a multi-layered decorative and protective coating thereon.
It is sometimes the practice with various brass articles such as faucets, faucet escutcheons, door knobs, door handles, door escutcheons and the like to first buff and polish the surface of the article to a high gloss and to then apply a protective organic coating, such as one comprised of acrylics, urethanes, epoxies and the like, onto this polished surface. This system has the drawback that the buffing and polishing operation, particularly if the article is of a complex shape, is labor intensive. Also, the known organic coatings are not always as durable as desired, and are susceptible to attack by chemicals such as bases and acids. It would, therefore, be quite advantageous if brass articles, or indeed other articles, either plastic, ceramic, or metallic, could be provided with a coating which provided the article with a decorative appearance as well as providing wear resistance, abrasion resistance and corrosion resistance. It is known in the art that a multi-layered coating can be applied to an article which provides a decorative appearance as well as providing wear resistance, abrasion resistance and corrosion resistance. This multi-layer coating includes a decorative and protective vapor deposited color layer of a refractory metal compound such as a refractory metal nitride, e.g., zirconium nitride or titanium nitride. Such a coating system is described, inter alia, in U.S. Pat. Nos. 5,552,233; 5,922,478; 5,654,108 and 6,033,790. However, these patents describe, and it is currently the practice, to provide an electroplated basecoat layer, such as nickel, over the substrate and beneath the vapor deposited layer(s). The application of the electroplated basecoat layer requires electroplating equipment which is cumbersome and expensive. It also requires a laborious and time consuming electroplating step on the article to be coated. It would thus be very advantageous if the electroplated basecoat could be eliminated or replaced by another basecoat such as a polymer basecoat. However, selecting a polymer that will function as an effective basecoat is more of an empirical art than an exact and predictable science. There is generally difficulty in predicting how a given polymer will behave as a basecoat. A polymer to be an effective basecoat must have good adhesion to both the substrate and the overlying vapor deposited layers. Otherwise the coating will delaminate. While some polymers may adhere well to the substrate, they may not provide sufficient adhesion to the vapor deposited layers, and vice versa. Furthermore, a polymer must be sufficiently hard or have sufficient shape memory so that it will not undergo permanent severe elastic deformation when the overlying hard vapor deposited layers are impacted by an object. Also, the polymer must be uniformly and completely distributed over the substrate surface. This may be difficult to achieve, especially if the article on which the polymer is deposited is of a complex or intricate shape. The present invention provides a polymer which is an effective basecoat.
The present invention is directed to an article such as a plastic, ceramic or metallic article having a decorative and protective multi-layer coating deposited on at least a portion of its surface. More particularly, it is directed to an article or substrate, particularly a metallic article such as stainless steel, aluminum, brass or zinc, having deposited on its surface multiple superposed layers of certain specific types of materials. The coating is decorative and also provides corrosion resistance, wear resistance and abrasion resistance. The coating provides the appearance of chrome, highly polished brass or of nickel, i.e. has a chrome, brass or nickel color tone. Thus, an article surface having the coating thereon simulates a brass or nickel surface.
The article first has deposited on its surface an epoxy urethane based polymeric basecoat layer. On top of the polymeric layer is then deposited, by vapor deposition such as physical vapor deposition, one or more vapor deposited layers. More particularly disposed over the epoxy urethane based polymeric basecoat layer is a protective decorative color layer comprised of a chromium, chromium compound, refractory metal compound or a refractory metal alloy compound.